Key Takeaways
A TRS jack lets you plug in stereo headphones, run balanced audio, and patch in effects with one socket.
Common sizes are ¼″ (6.35 mm), ⅛″ (3.5 mm), and 2.5 mm—look for IEC specs or MIL-SPEC for pro gear.
Stereo (unbalanced) uses Tip = left, Ring = right, Sleeve = ground; balanced mono uses Tip = hot, Ring = cold, Sleeve = ground to cut noise.